水平井变密度射孔技术研究

Research on Variable Density Perforating Technology of Horizontal Well

射孔是水平井完井的主要方式之一,由于流体在水平井筒内的流动为变质量流,在水平井筒内必然因流体的流动而引起压力损失,主要包括摩擦压力损失、加速压力损失以及混合压力损失。以渗流理论和流体力学相关知识为基础,考虑地层流体和井筒流体的相互耦合作用以及现场的实际需要,对水平井变密度射孔技术进行了研究,推导出以椭圆形泄油面积结合矩形泄油面积为基础的水平井变孔密射孔的油藏渗流模型、井壁入流模型及井筒压降模型,并分析了孔眼密度变化对水平井产量及井筒压降的影响。该研究为油田现场应用水平井变密度射孔完井提供了理论依据。

Perforation is one of the main way of horizontal well completion.Due to the variable mass flow in the horizontal wellbore,pressure loss was caused in the horizontal wellbore,mainly including frictional pressure loss,acceleration pressure loss and flow mixing pressure loss.Based on the permeability theory and fluid mechanics knowledge,couple effects between formation fluid and flow in the wellbore and oilfield work needs,the mechanism of the variable perforation density was studied.Based on elliptical discharge oil area and rectangular drainage oil area,reservoir permeability computational models,flow computational models from formation into the horizontal wellbore and pressure drop computational models in the horizontal wellbore were derived.And we also analyzed the influence of perforation density changes on production of horizontal well and the wellbore pressure drop.The research result of this paper provides a theoretical basis for the application of horizontal wells variable density perforation in the oilfield.